The invention relates generally to fluid back flow prevention, and more particularly to a simple, effective, flow controller operating to allow drainage of fluid forward flow while back flow is prevented.
There is need for a simple, effective and reliable back flow preventing device, which also functions to discharge fluid accumulation in a line leading to the device. There is also need to minimize the possibility of freeze-up of fluid accumulation in such a device.
There is additional need for providing a device, as referred to, in combination with a hydrant structure.